ML20210A705
| ML20210A705 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 09/15/1986 |
| From: | SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | |
| Shared Package | |
| ML20210A695 | List: |
| References | |
| NUDOCS 8609170314 | |
| Download: ML20210A705 (5) | |
Text
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Attachment i
Page 1 of 5 REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued) 1.
All nonplugged tubes that previously had detectable wall penetrations greater than 20%.
2.
Tubes in those areas where experience has indicated potential problems.
3.
A tube inspection (pursuant to Specification 4.4.5.4.a.8) shall be performed on each selected tube.
If any selected tube does not permit the passage of the eddy current probe for a tube inspection, this.shall be recorded and an adjacent tube shall See INSERT A be selected and subjected to a tube inspection, d. cf.
The tubes selected as the second and third samples -(if required by'
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Table 4.4-2) during each inservice inspection may be subjected to a partial tube inspection provided:
1.
The-tubec selected for these samples include the tubes from
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those areas of the tube sheet array where tubes with imperfections were previously found.
2.
The inspections include those portions of the tubes where imperfections were previously (Nart.
The results of each sample inspection shall be classified into one of the following three categories:
Category Inspection Results C-1 Less than 5% of the total tubes inspected are l
degraded tubes and none of the inspected tubes are defective.
C-2 One or more tubes, but not more than 1% of the i
total tubes inspected are defective, or between 5% and 10% of the total tubes inspected are degraded tubes.
C-3 More than 10% of the total tubes inspected are degraded tubes or more than 1% of the inspected tubes are defective.
Note:
In all inspections, previously degraded tubes must exhibit significant (greater tha'n 10%) further wall penetrations to be included in the above percentage calculaticns.
INSERT A
- c. In addition to the sample required in 4.4.5.2 b.1 through 3, all tubes which have had the-F* criteria applied will be inspected in the tubesheet region. These tubes may be excluded from 4.4.5.2 b.1 provided the only previous wall penetration of>20%
was located below the F* distance.
SupMER - UNIT 1 3/4 4-12 8609170314 860915 PDR ADOCK 05000395 p
Attachment Page 2 of 5 REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued) 4.4.5.4 Acceptance Criteria a.
As used in this Specification:
1.
Imperfection means an exception to the dimensions, finish or contour of a tube from that required by fabrication drawings or specifications.. Eddy-current testing indications below 20% of the nominal tube wall thickness, if detectable, may be considered as imperfections.
2.
Degradation means a service-induced cracking, wastage, wear or general corrosion occurring on either inside or outside of a:
tube.
3.
Degraded Tube means a tube containing imperfections greater than or equal to 20% of the nominal wall tnickness caused by degradation.
4.
% Degra'dation means the percentage of the tube wall thickness affected or removed by degradation.
5.
Defact means an imperfection of such severity that it exceeds the plugging limit. A tuoe containing a defect is defective.
6.
Plugging 'imit means the imperfection depth at or beyond which the tube shall be removed from service and is equal to 40% of the nominal tube wall thickness. See INSERT B l
7.
Unserviceable describes the condition of a tube if it leaks or contains a defect large enough to affect its structural integrity in the event of an Operating Basis Earthquake, a loss-of-coolant accident, or a steam line or feedwater line break as specified in 4.4.5.3.c. above.
8.
Tube Inspection means an inspection of the steam generator tube from the point of entry (hot leg side) completely around the U-bend to the top support of the cold leg.
l INSERT B This definition does not apply to the area of the tubesheet region-below the F* distance provided the tube is not degraded (i.e., no indications of cracking) within the F* distance.
4 SUMMER - UNIT 1 3/4 4-14 8
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Attachment Page 3 of 5
, REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued)
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9.
Freservice Inspection means an inspection of the full length of s
each tube in each steam generator performed by addy current techniques prior to service to establish a baseline condition of the tubing. This inspection shall be performed after the field hydrostatic test and prior to initial POWER OPERATION using the equipment and techniques expected to be used during
"'E' See INSERT C b.
The steam generator shall be determined OPERA 8LE after completing g
the corresponding actions (plug all tubes exceeding the plugging limit and all tubes containing through-wall cracks) required by Table 4.4-2.
4.4 5.5 Reports
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_s a.
Within 15 days following the completion of each inservice inspection of steam generator tubes, the number of tubes plugged in each steam generator shall be reported to the Commission in a Special Report pursuant to Specification 6.9.2.
b.
The complete results of the steam generator tube inservice inspection shall be submitted to the Commission in a Special Report pursuant to Specification 6.9.2 within 12 months following the completion of the
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inspectica This Special Report shall include:
1.
Number and extent of tubes inspected.
l 2.
Location and percent of wall-thickness penetration for each indication of an imperfection.
1 3.
Identification of tubes plugged.
c.
Results of steam gecerator tube inspections which fall into Category C-3 and require prompt notification of the Commission shall be reported pursuant to 10 CFR 50.72(b)2(1). prior to resumption of plant operation. A report pursuant to 10 CFR 50.73(a)2(ii) shall be submitted to provide a description of investigations conducted to
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determine cause of the tube degradation and corrective measures taken to prevent recurrence.
d.
The results of inspections of F* tubes shall be reported to the Commission in a report to the Director, ONRR, prior to the restart of the unit following the inspection. This report shall include:
1.
Identification of F* tubes, and 2.
Location and size of the degradation.
NRC approval of this report is not required prior to restart.
SupMER - UNIT 1 3/4 4-15 Amendment No. 35 t
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Attachment Page 4 of 5 INSERT C 10.
F*
Distance is the distance into the tubesheet from the face of the tubesheet
.or the top of the last hardroll, whichever is lower (futher into the tubesheet) that has been' conservatively chosen to be 1.6 inches.
11.
F# TUBE is the tube with. degradation equal to or greater than 40%,
below the F*
distance and not degraded (i.e.,
no indications of cracking) within the F#
distance.
The application of F*
expires at the end of the fifth fuel cycle.
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..4 Attachcent Page 5 of 5 4..
e.
AEACTOR COOLANT SYSTEM
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BASES 3/4.4.5 STEAM GENERATORS The Surveillance Requirements for inspection of the steam generator tubes
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ensure that the structural integrity of this portion of the RCS will be main-tained. The program for inservice inspection of steam generator tubes is based on a modification of Regulatory Guide 1.83. Revision 1.
Inservice inspection of steam generator tubing is essential in order to maintain surveillance of the conditions of the tubes in the event that there is evidence of mechanical damage or progressive degradation due to design, manufacturing errors, or inservice l
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conditions that lead to corrosion.
Inservice inspection of steam generator tubing also provides a means of characterizing the nature and cause of any tube degr,adation so that corrective measures can be taken.
Theplantisexpectedtobeoperatedinamannersuchthatthesecoridary coolant will be maintained within those chemistry limits found to result in
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negligible corrosion of the steam generator tubes.
If the secondary coolant chemistry is not maintained within these limits, localited corrosion may litaly result in strkss corrosion cracking.
The extent of cracking during plant operation would be limited by the limitation of : team generator tube leakage between the primary coolant system and the secondary coolant system (primary-to-secondary leakage = 500 gallons per day per steam generator).
Cracks having a primary-to-secondary leakage less than this limit during operation will have an adequate margin of safety to withstand the loads
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imposed during notmal operation and by postulated accidents. Operating plants have demonstrated that primary-to-secondary leakage of 500 gallons per day per steam generator can readily be detected by radiation monitors of steam generator
- blowdown, i.eakage in excess of this limit will require plant shutdown and an unscheduled inspi.ction, during which the leaking tubes will be located and plugged.
Wastage-type defects are unlikely with proper chemistry treatment of the secondary coolant.
However, even if a defect should develop in service, it will be found during scheduled inservice steam generator tube examinations.
Plugging will be required for all tubes with imperfections exceeding the plugging limit of 40% of the tube nominal wall thickness.
Steam generator tube inspections of operating plants have demonstrated the capability to
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reliably detec degradation that has penetrated 20% of the original tube wall z
thickness.
wastage -type 8** MRT D Whenever the results of any steam generator tubing inservice inspection fall into Category C-3, these results will be promptly reported to the Commission pursuant to 10 CFR 50.72(b)2(i) prior to resumption of plant operation.
Such j
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cases will be considered by the Commission on a case-by-case basis and may 1
result in a requirement for analysis, laboratory examinations, tests, additional eddy-current inspection, and revision of the Technical Specifications, if necessary.
INSERT D For tubes with degradation below the F* distance, but not degraded within the F* distance, plugging is not required.
St#MER - UNIT 1 8 3/4 4-3 Amendment No.
35 l
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